/Engine/Source/Editor/UnrealEd/Public/EditorWorldExtension.h
Find an extension based on the class
The first extension that is found based on class
[UEditorWorldExtension](API\Editor\UnrealEd\UEditorWorldExtension) * FindExtension ( [TSubclassOf](API\Runtime\CoreUObject\Templates\TSubclassOf)< [UEditorWorldExtension](API\Editor\UnrealEd\UEditorWorldExtension) > EditorExtensionClass )